Primitives

I've been going deep into the guts of Git lately, and I have to say it's really beautiful. Not the code necessarily, but the purity of the design, the primitives on which the system is built. Everything follows so simply from just a few initial concepts. You have a content-addressable object store which stores files, or trees of files, or commits which point to trees and other commits. Because everything is based on the hash of its contents, each commit forms a Merkle tree that uniquely identifies everything, from the commit itself to the commits before it to the trees and files themselves. Gorgeous.

To me that is the absolute essence of great code, to find a minimal set of concepts with maximal conceptual power. You can really feel the difference between a system that has been built on elegant foundations and one that's just compromise upon compromise trying to make up for an irredeemable core. Good primitives are often so pure and powerful that they extend beyond code and end up more like philosophical tools. A content-addressable store is the idea of referring to things by a description of what they are, rather than an arbitrary label. Git's way of representing history is the idea that you can get rid of time entirely, and just define the past as the set of things that must have happened for the present to be like it is now.

It's extraordinarily satisfying when you learn a new primitive that opens up a whole new class of follow-on ideas. Even more satisfying is when you are struggling to find the right set of primitives to build something powerful on, and then everything suddenly clicks into place.

But the most satisfying of all – I assume – is discovering a brand new primitive. Something that nobody's thought of before. Relatively few people have found ideas that powerful, but it must really be something to unearth a whole new way of thinking, like peering into the universe itself.